Some MLS questions?

I've just played my first season in the MLS, and I was wondering, how does the expansion draft work? I have a transfer arranged for a player and am unsure what happens if I leave him unprotected. Also, how do I keep a team like TFC afloat? I am strugling in finances atm, as Bradley and Defoe are just eating away each week and month at my finance with 300k to the two of them.... is there a way to somehow keep them? How does a team like LA do it? (Keane and Donovan are 200k a week in total)? I don't want to sell Bradley as he's amazing, but I've already sold Defoe.